I don't want to bum anyone out, but I think the jury should still be out on this one. Although I have never seen colored verrucae on a haddoni, and I don't think her book in the last word in clownfish host anemones, Daphne Fautin says in her description of S. haddoni as sometimes having light rose to purple verrucae.
In the same picture that shows the purple verrucae, the tentacles on the edge look very haddoni-ish. I also think I may be seeing exocoelic tentacle differences.
I would love it to be a gigantea, so I would have a little more credibility as seeing one myself (in my eyes as well), but I am not sure it is. Hopefully Reefvette can see it in person and give a definite ID.